4802x324=1555848     

1555848

802x32

4802 x 324 = 1555848

\(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{3\cdot2+7}{14}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)

\(\left[\dfrac{6}{14}+\dfrac{7}{14}\right]^2=\left[\dfrac{13}{14}\right]^4=\dfrac{169}{196}\)

\(\left(\dfrac{3}{7}+\dfrac{1}{2}\right)^2=\left(\dfrac{13}{14}\right)^2=\dfrac{169}{196}\)

`A=sqrt{3-2sqrt2}-sqrt{3+2sqrt2}`

`=sqrt{2-2sqrt2+1}-sqrt{2+2sqrt2+1}`

`=sqrt{(sqrt2-1)^2}-sqrt{(sqrt2+1)^2}`

`=|sqrt2-1|-|\sqrt2+1|`

`=sqrt2-1-sqrt2-1=-2`

Ta có: \(A=\sqrt{3-2\sqrt{2}}-\sqrt{3+2\sqrt{2}}\)

\(=\sqrt{2}-1-\sqrt{2}-1\)

=-2

Ta có: \(A=2^{100}-2^{99}-2^{98}-...-2^2-2-1\)

\(\Leftrightarrow2A=2^{101}-2^{100}-2^{99}-...-2^3-2^2-2\)

\(\Leftrightarrow2A-A=2^{101}-2^{100}-2^{99}-...-2^3-2^2-2-2^{100}+2^{99}+2^{98}+...+2^2+2+1\)

\(\Leftrightarrow A=2^{101}-2\cdot2^{100}+1\)

\(\Leftrightarrow A=1\)

Thank you

a) 3,125 + 2,075 x 2 = 3,125 + 4,15 = 7,275 .

b) (3,125 + 2,075) x 2 = 5,2 x 2 = 10,4

50 chục

a) \(3.125+2.075\cdot2=3.125+4.15=7.275\)

A = 2^2 + 4^2 + 6^2 +...+ 100^2

A = (2.1)^2 + (2.2)^2 + ... + (2.50)^2

A = 2^2.1^2 + 2^2.2^2 + ... + 2^2.50^2

A = 2^2(1^2 + 2^2 + ... + 50^2)

A = 4.\(\frac{5.\left(50+1\right).\left(2.50+1\right)}{6}\)

A = 4.4292,5 = 17170

a: =3/5+1/3=9/15+5/15=14/15

b: =-3:2/7=-3x7/2=-21/2

3/4 x 3/2 = 9/8

3/2 - 1/3 = 7/6

3/4x3/2=9/8

3/2-1/3=7/6

a, = 3/4 x 3/2 = 9/8

b, 3/2 - 1/3 = 7/6 

a,=(2a + b - 3c).(2a + b - 3c)

=4a\(^2\)+2ab-6ac+2ab+b\(^2\)-3bc-6ac-3cb+9c\(^2\)

=4a\(^2\)+b\(^2\)+9c\(^2\)+4ab

=2\(^2\).a\(^2\)+4ab+b\(^2\)+9c\(^2\)

=(2a+b)\(^2\)+9c\(^2\)( đáng lẽ chỗ này nó phải là -9c\(^2\) nhưng t ko ra đc )

b,=(a + 2b + 3c - 4d)(a + 2b + 3c - 4d)

=a\(^2\)+2ab+3ac-4ad+2ab+4b\(^2\)+6bc-8bd+3ac+6bc+9c\(^2\)-12cd-4ad-8bd-12cd+16d\(^2\)

=a\(^2\)+4b\(^2\)+9c\(^2\)+16d\(^2\)+4ab+6ac-8ad+12bc-16bd-24cd

=(a\(^2\)+4ab+4b\(^2\))+(9c\(^2\)-24cd+16d\(^2\))+6ac-8ad+12bc-16bd

=(a+2b)\(^2\)+(3c-4d)\(^2\)+2(3ac-4ad+6bc-8bd)

=(a+2b)\(^2\)+(3c-4d)\(^2\)+2[a(3c-4d)+2b(3c-4d)]

=(a+2b)\(^2\)+(3c-4d)\(^2\)+2(a+2b)(3c-4d)

khiếp bài dài nghoằng ra ý :(